In some areas of the world such as developing countries, there is a particular need for technology to assist in providing mobility to people with disabilities, regardless of their location, travel requirements, or local environment. It has been estimated, for example, that 20 million people in the developing world require a wheelchair (Annual Program Statement. USAID, 2003), yet wheelchairs are only available to about five percent of those in need (Warner, D., Nothing About Us Without Us: Developing Innovative Technologies For, By and With Disabled Persons, 1998). About seventy percent of disabled people in the developing world live in rural areas, such that the availability of public transportation is minimal (Groce, N. E., Health beliefs and behaviour towards individuals with disability cross-culturally. Introduction to Cross-Cultural Rehabilitation: An International perspective, 1999). People with disabilities are profoundly affected by the lack of access to mobility aids. For example, ninety-eight percent of children with disabilities in developing countries do not attend school (People with disabilities. UNESCO Bangkok, 2003. IV(APPEAL)). Moreover, discrimination in the developing world has even resulted in double-charging for bus fares, simply due to an alleged added transportation cost for a wheelchair (Amos G. Winter, V., Assessment of Wheelchair Technology in Tanzania. The International Journal of Service Learning in Engineering, 2006. 1(2): p. 60-77). In short, the ability of disabled individuals in the developing world to travel to a job and even to be a functional member of their society is limited by the lack of readily available mobility aids.
Conventional, western-style wheelchairs have limited usefulness to the disabled in developing countries. These wheelchairs are inefficient to propel and can be exhausting to use over long distances and on the rough terrain typical in such countries. Furthermore, these wheelchairs are most often manufactured abroad with components that are not locally-available, and thus once a part on the wheelchair breaks or exhausts its expected service life, the original part cannot be readily replaced (if at all) with a spare or replacement part. It has even been found that locally-manufactured wheelchairs still employ custom and relatively expensive components that prevent would-be purchasers from owning them.
Thus, there is a need for a wheelchair-based mobility aid that can be readily manufactured throughout the world using off-the-shelf parts, such as bicycle parts, yet be functional and operational on varied terrain ranging from steep hills to sandy roads to muddy walking paths to home-based situations. There also is a need for a wheelchair-based mobility aid with enhanced performance breadth for users in developed countries.